if (RX_MATCH_TAINTED(rx)) /* run time pattern taint, eg locale */
rxtainted |= SUBST_TAINT_PAT;
m = orig + RX_OFFS(rx)[0].start;
d = orig + RX_OFFS(rx)[0].end;
s = orig;
if (m - s > strend - d) { /* faster to shorten from end */
if (RX_MATCH_TAINTED(rx)) /* run time pattern taint, eg locale */
rxtainted |= SUBST_TAINT_PAT;
m = orig + RX_OFFS(rx)[0].start;
d = orig + RX_OFFS(rx)[0].end;
s = orig;
if (m - s > strend - d) { /* faster to shorten from end */